1. Technical Field
The present invention relates to a spindle arrangement for a non-driven, steerable vehicle wheel for motor vehicles, comprising a spindle unit with bores, located at an axial distance from one another and aligned axially with one another, for rotatable mounting of the spindle unit relative to a kingpin accommodated via a central portion in a through-bore in a front axle-beam, a stub axle unit which is connected to the spindle unit and on which a wheel hub is mounted, and, arranged at a first and second end of the kingpin, bearing means for the rotatable mounting of the spindle unit.
2. Background of the Invention
A spindle arrangement is used to make it possible to steer a motor vehicle, such as a lorry. The spindle arrangement is coupled to a vehicle wheel which is made steerable by means of the spindle arrangement.
A common type of spindle arrangement for lorries has a spindle unit mounted in a conical roller bearing at the upper end of the kingpin and a radial sliding bearing at its lower end. The upper bearing takes up both axial and radial forces, while the lower takes up only radial forces. In such a spindle mounting, the axial force on the upper bearing is load-dependent, for which reason the axial loading on the bearing varies with the total weight on the vehicle. Under particular driving conditions, such as during cornering with a great load, a torque arises in the spindle arrangement, which is taken up by the radial sliding bearing. The torque taken up by the radial sliding bearing can result in a certain play occurring between the bearing surfaces of the radial sliding bearing.
One object of the present invention is to produce a spindle arrangement which is non-sensitive to torque forces acting on the spindle arrangement.
Another object of the invention is to produce a spindle arrangement which has a long useful life.
This is achieved by means of a spindle arrangement of the type indicated above in which the bearing means at the first end of the kingpin is a spherical sliding bearing and in which the kingpin is oriented in such a manner in relation to the spindle unit that the spherical sliding bearing takes up only radial forces in relation to the center axis of the kingpin.
The spherical sliding bearing allows a relative displacement between the bearing surfaces of the sliding bearing in a direction of rotation about an axis transverse to the center axis of the kingpin. This displacement arises from the torque which acts on the spindle arrangement. By virtue of the spherical sliding bearing, the point loads which would otherwise arise in a radial sliding bearing are avoided. The forces which arise in the spherical sliding bearing are evened out over a large area between the bearing surfaces of the spherical sliding bearing. Low wear of the spherical sliding bearing is thus obtained, which results in a long useful life of the spindle arrangement.